20 ALASKAN GLACIER STUDIES
valley glaciers, as is testified by cirques, hanging valleys, transported bowlders, etc., in the Kigluaik, Bendeleben, York, Cape, and Ear Mountains. This is chiefly the result of studies by Brooks,1 Collier, Smith, Eakin and Moffit.
THE GLACIATION OF ALASKA
The phenomena of former glaciation in Alaska have been treated incidentally in the preceding pages dealing with existing glaciers, and more fully in some of the reports there cited. Several reports, referred to below, have dealt especially with the general phenomena of Alaskan glaciation.
After Russell's visit to Alaska in 1889 he wrote his Notes on the Surface Geology of Alaska,2 pointing out that northwestern North America had not been buried beneath a continental glacier when northeastern North America was ice-covered, but that in the appropriate part of Alaska "the ice age still lingers." At about the same time Dawson was writing his suggestive papers8 on the glaciation of Yukon Territory and British Columbia in which he deals incidentally with parts of the Alaskan border, particularly from Mt. St. Elias to Dixon Entrance, and shows the extent of glaciation there.
After Gilbert's summer in Alaska with the Harriman Expedition in 1899, he published his wonderfully comprehensive descriptions of the existing glaciers observed, and then wrote on the Pleistocene glaciation, dealing especially with the physiographic forms produced by glaciation in the coastal region.4
In Brooks's Geography and Geology of Alaska6 there is an excellent summary of the knowledge as to the glaciation of Alaska, accompanied by a map which showed the existing glaciers and snowfields, the glaciated areas, the neve fields and areas in part above ice sheets during maximum glaciation, the directions of ice movement, and the areas of post-glacial silts, sands, and gravels. Other writers have discussed glaciation,6 and Hayes,
i Brooks, A. H., A Reconnaissance of the Cape Nome and Adjacent Gold Fields of Seward Peninsula, Alaska House Doc. 547, 56th Congress, 2d Session, Washington, 1901, pp. 43-47.
Brooks, A. H. and Collier, A. J., Science, N. S., VoL XTTT, 1901, pp. 188-180.
Collier, A. J., Professional Paper 2. U. S. Geol. Survey. 1902, pp. 28-29; Bull. 828, TJ. 8. Geol. Surrey, 1908, pp. 94-99.
Smith, P. S., Bull. 433, U. S. Geol'. Survey, 1910, pp. 48, 185-187.
Smith, P. S. and Eakin, H. M., Bull. 449, U. S. Geol. Survey, 1911, pp. 88-86, 99.
Moffit, F. H., Bull, 638, U. S. Geol. Survey, 1918, pp. 14, 87, 61-63.
' Russell, I. C., Bull Geol. Soc. Amer., Vol. I, 1890, pp. 99-154.
1 Dawson, G. M., Recent Observations on the Glaciation of British Columbia' and Adjacent Regions; Geog. Mag., 3d Decade, Vol. V, 1888, pp. 847-850; Amer. Geol., VoL m, 1889, pp. 249-253; Geol. Nat. Hist. Survey Canada, Vol. IE, PL 1, 1889. pp. 88B-43B; On the Later Physiographical Geology of the Rocky Mountain Region in Canada with Special Reference to Changes in Elevation and the History of the Glacial Period, Trans. Roy. Soc. Canada, Vol. VHI, sect. IV, 1890, pp. 25-74 and PL II,"No. 4; Amer. Geol., Vol. VL 1890, pp. 153-162.
* Gilbert, G. K, Harriman Alaska Expedition, VoL HJ, Glaciers, 1904, pp. 118-194; Nat. Geog. Mag., Vol. XV, 1904, pp. 449-450.
* Brooks, A. H., Professional Paper 45, U. S. Geol. Survey, 1906, pp. 245-249, and Pis. XII and TYH,
* DalL W. H., Alaska and Its Resources, Boston, 1870, pp. 461-464.
Wright, G. F., Notes on the Glaciation of the Pacific Coast, Amer. Naturalist, Vol. Tna. 1887, pp. 250-258.
Tarr, R. S., The Glaciers and Glaciation of Alaska, Science, N. S., Vol. XXXV, 1912, pp. 241-258; Annals Assoc. Amer. Geog., Vol. II, 1912, pp. 8-24.